The interference between the optical paths in a broadband astignatism-free Gzerny-Turner spectrometer which uses spherical optics and a plane grating was introduced theoretically. To eliminate the interference, the zeroth-order and first-order astigmatism-free conditions of the Czerny-Turn-er spectrometer was researched and several situations of optical path interference satisfied the astigmatism-free conditions were analyzed. Based on the astigmatism-free conditions and avoidance conditions of optical structure interference, the selection principles of the incidence angles θc and θF were deduced, and the optimization approach was summarized. Then, the optical system of Czerny-Turner spectrometer which will be loaded on a spacecraft was designed according to the method whose selection principle was verified by using ray-tracing method. The results show that the obtained imaging quality has a good spectral resolution, which validates that the Czerny-Turner spectrometer can satisfy the requirements both for eliminating astigmatism and for avoiding optical structure interference .Inconclusion,the method can help the spectrometer more compact and more efficient.%理论分析了准直镜和聚焦镜采用球面面型的Czerny-Turner光谱仪系统中由消像散条件引起系统发生光路与结构件干涉的现象.为了在设计阶段就克服这种干涉问题,提出了Czerny-Turner结构的防干涉设计条件.结合消像散条件及光路结构防干涉条件,总结出了Czerny-Turner光谱仪消像散优化和结构优化的设计步骤,提出了准直镜入射角θc和聚焦镜入射角θF的选定准则.对根据总结的设计步骤及入射角选定准则设计的光谱仪系统进行了光线追迹法验证,发现其既能满足消象散条件又不会发生光路与结构件的干涉现象,能满足航天遥感对其宽谱段、高分辨率的要求.
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